Theon Design 419 hp air-cooled 911 with F1 carbon body

Theon Design’s latest commission pairs a 4.0 liter flat-six tuned to 419 hp with extensive carbon fiber bodywork claimed to be F1 grade, a combination the company says helps shave the car to a total mass of 1,150 kg (2,535 lbs).

Unveiled as a bespoke air-cooled Porsche 911 built specifically for UK roads, the coupe was developed over an 18-month collaboration between client and builder. The package includes selectable engine maps, a G50 five-speed manual gearbox, semi-active dampers and bespoke spring rates, all calibrated to deliver sharper handling and improved ride compliance compared with stock, according to Theon Design.

Construction and performance

Theon says the exterior bodywork, bumpers, lower sill panels and various trim elements are formed from carbon fiber — described by the company as F1 grade — and that the composite program accounts for roughly a 300 kg (661 lbs) reduction compared with a standard shell. The finished car weighs 1,150 kg (2,535 lbs), which Theon calculates as about 364 hp per metric ton.

The 4.0 liter naturally aspirated engine produces 419 hp and 322 lb-ft (437 Nm) of torque. Theon quotes a zero to 60 mph time of about 4.0 seconds and points to selectable engine maps for drivability variations. Final drive and shift feel come via a G50 five-speed manual transmission.

Interior and development process

Inside, the build uses Beechwood semi-aniline and nubuck leather with champagne detailing, Recaro CS seats, revised window switches and a fully electric heating and air-conditioning system. Exterior details, including the Porsche script, wheels, brake discs and calipers, are finished to match the Oak Green Neo Metallic paint, an updated take on the classic Oak Green Metallic.

On the commission process, Theon Design co-founder Adam Hawley said, "As with every commission Theon Design undertakes, this project began by listening to what the client wanted – not just how they wanted their car to look, but how they wanted it to feel. That informed every aspect of the development program, from the engine, transmission, and brake package to spring rates, damper calibration, and steering response."

Hawley added, "Throughout the eighteen-month development period, we spoke regularly with the client, involving them in all the decisions that would affect the car’s character. From the first conversation to the final sign-off drive, collaboration is key and ensures that the ownership experience is every bit as personal and rewarding as the design."

Theon also confirmed work is progressing on a more extreme model, the Theon R, which the company says will exceed 500 hp, employ motorsport-derived technology and target a curb weight under 1,000 kg (2,200 lbs).